To me compared to old versions, some parts of combat have gotten easier and other parts harder. When the player is on horseback, the AI on foot is more willing to try and hit you rather than just stand there and take it. They also block much more consistently in this scenario. On the other hand, when the player and AI are both on foot they actually block less consistently than the old versions. Also they sometimes take a step back so they don't quite swarm you as quickly. On the other hand, they also try to flank you on foot too so they can catch you off guard. So it's kind of a mixed bag.
Ranged enemies also are generally less accurate than in previous versions. I don't always bother carrying shields anymore when I'm on horse since so long as you change direction every so often, you almost never get hit. Once I get a charger and lance, I can easily solo sea raiders without using a shield. But soloing enemy horsemen is a lot more difficult now since they block much more often. It used to be you can just keep circling around and leading a pack of enemy horsemen while slashing as you pass by them and easily kill them all. But doing that now, they block at least 75% of the hits.